Auxin plant growth regulators

Abstract

Compositions and methods for enhancing plant growth in a flowering plant having an auxin response pathway by applying an effective amount of a composition comprising an auxin or auxin analog to the plant, or a portion thereof, or a locus thereof, at or before an early reproductive stage of the plant. The enhanced plant growth may ameliorate the effects of abiotic stress and/or improve fruit or seed yield.

1 .- 22 . (canceled) 
     
     
         23 . A method of enhancing plant growth in a flowering plant comprising an auxin response pathway, comprising applying, at or before an early reproductive stage of the plant, an effective amount of a composition comprising an auxin or auxin analog to the plant, or a portion thereof, or a locus thereof. 
     
     
         24 . The method of  claim 23 , wherein the plant is selected from the group consisting of a plant from the Leguminosae (Fabaceae) family, a plant from the Brassicaceae (Cruciferae) family, a fruiting vegetable plant, and a crop plant in the Poaceae (Gramineae) family. 
     
     
         25 . The method of  claim 24 , wherein the plant is selected from the group consisting of soybean, pea, canola, tomato and wheat plants. 
     
     
         26 . The method of  claim 23 , wherein the composition is applied at anthesis or least one day prior to anthesis. 
     
     
         27 . The method of  claim 23 , wherein the composition is applied at least one week prior to anthesis. 
     
     
         28 . The method of  claim 23 , wherein the plant is a soybean or pea plant, and the composition is applied at or before anthesis. 
     
     
         29 . The method of  claim 28 , wherein the composition is applied at a time when floral buds are not visible outside of stipule leaves. 
     
     
         30 . The method of  claim 24 , wherein the plant is a plant from the Brassicaceae (Cruciferae) family, and the composition is applied at or before a green bud stage. 
     
     
         31 . The method of  claim 24 , wherein the plant is a plant from the Poaceae (Gramineae) family, and the composition is applied at or before a late boot stage, where the inflorescence has not emerged from the boot, or where the inflorescence recently has emerged from the boot. 
     
     
         32 . The method of  claim 23 , wherein the auxin or auxin analog comprises a 4-substituted indole-3-acetic acid. 
     
     
         33 . The method of  claim 32 , wherein the auxin or auxin analog comprises 4-methyl-indole-3-acetic acid. 
     
     
         34 . The method of  claim 32 , wherein the auxin or auxin analog comprises 4-chloro-indole-3-acetic acid. 
     
     
         35 . The method of  claim 23 , wherein the composition further comprises one or more selected from the group consisting of insecticides, acaricides, herbicides, fungicides, safeners, fertilizers, and additional plant growth regulators. 
     
     
         36 . The method of  claim 35 , wherein the composition further comprises one or more of a cytokinin and a gibberellin. 
     
     
         37 . The method of  claim 23 , wherein the auxin or auxin analog is applied at a concentration from about 1×10 −4  to about 1×10 −7  M in aqueous solution. 
     
     
         38 . The method of  claim 23 , wherein the composition is applied to a crop at a rate of about 0.0001 to 20 g/hectare. 
     
     
         39 . The method of  claim 23 , wherein the composition is applied to a crop at a rate of about 3.4 mg to about 3.8 g per acre. 
     
     
         40 . The method of  claim 23 , wherein the method ameliorates symptoms of abiotic stress in the plant. 
     
     
         41 . The method of  claim 40 , wherein the abiotic stress comprises one or more selected from the group consisting of drought, salinity, and temperature (heat or cold) stress. 
     
     
         42 . The method of  claim 40 , wherein the plant exhibits a plant growth response increase or benefit of 10% or more. 
     
     
         43 . The method of  claim 23 , wherein the plant exhibits increased fruit or seed yield. 
     
     
         44 . The method of  claim 43 , wherein the fruit or seed yield is increased by 10% of more.